The key to good coffee is in the way it's roasted.

This is why the Italian tech company PuroSole has decided to develop an innovative installation that is capable of roasting coffee beans with renewable energy.

The three co-founders of the project spent almost six years developing an efficient way to use solar power.

"It's the coffee, not the rotating basket or the air in it that we are heating, the sun's rays hitting coffee beans, heating them and causing the heating of the air surrounding it.

"But, essentially, the warmest part of all of this is the bean itself," says Daniele Tommei, one of the cofounders of PuroSole.

PuroSole's goal is to drastically reduce the cost of large thermodynamic plants and come up with a small motorized reflector that is completely self-sufficient.

Electronic engineer and cofounder of PuroSole, Antonio Durbè, says they don't use fossil fuels like gas or electricity; instead, it's purely and directly derived from solar energy that is being concentrated on the bean.

The founders claim they save over 400 kilos of Co2 in every tonne of roasted coffee. The company is currently making their own coffee and selling it online.